Objective: Studies investigating the comparison and interchangeability of transthoracic (TTE) and transesophageal echocardiography (TEE) regarding left ventricular (LV) systolic and diastolic function are limited. Therefore, in this study, we aimed to investigate agreement between TTE and TEE in the assessment of LV systolic functions by longitudinal myocardial deformation imaging (strain-S and strain rate-Sr) and LV diastolic functions by conventional Doppler parameters. Methods: Thirty-five patients underwent a clinically indicated cross-sectional study on agreement between two methods. All the patients underwent TEE right after TTE. From both TTE and TEE Doppler parameters such as early and late diastolic velocities (E, A, E’ and A`) deceleration time (DT), averaged mitral annular systolic velocity (Sm), isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), ejection time (ET), myocardial performance index (MPI) and longitudinal deformation imaging parameters (S, Sr) and systolic velocities were recorded. Agreement between TTE and TEE were evaluated by Bland-Altman analysis. Results: Bland-Altman analysis showed good agreement between TEE and TTE in terms of E, A, DT, E’, A’, IVRT, IVCT, ET and MPI measurements. However, there was poor agreement in segmental systolic velocities and segmental Sr parameters assessed by TTE and TEE. Besides, septal wall segmental S analysis showed a better agreement than lateral wall segmental analysis between TTE and TEE recordings. Conclusion: TTE and TEE conventional Doppler parameters are compatible in the assessment of LV diastolic function; however, agreement was poor in longitudinal deformation parameters that have been used in the quantitative assessment of LV systolic function between two methods and cannot be used interchangeably.